Computer disk drive systems are comprised of two main components, a Head Disk Assembly ("HDA") and the Printed Circuit Board Assembly ("PCBA"). Either or both of these components may fail during use. In order to enhance quality control and prevent disk drive failures in the field, a method of testing disk drives was needed. The present invention is concerned with testing disk drive systems for power related failures. This is accomplished using a power simulator.
In analyzing disk drive failures, it was determined that a sizable fraction of such failures resulted from anomalous power supply conditions. The present art lacks an effective tool for rapidly and effectively analyzing the effects of abnormal or extreme power supply conditions on disk drive systems. The Universal Power Simulator ("UPS") is a testing apparatus for analyzing disk drive performance while the disk drives are subjected to a series of simulated power anomalies. This testing provides the manufacturer with accurate quality control information regarding power related disk drive failures. UPS testing of disk drive systems also insures that defective disk drives are detected and selected out before such drives are marketed. The UPS accomplishes this goal by simulating a wide range of anomalous power conditions (e.g. hot plugging, slow or fast ramp power conditions, ringing, bounce, voltage spikes, voltage dips, power transients, etc.) known to cause disk drive failures. The UPS accomplishes this task in conjunction with a host computer, a programmable power supply, a series of plug-in computer cards, and an application specific computer program.